The applicant has discovered in chickens what appears to be a new pancreatic hormone. This "hormone" is a polypeptide of 36 amino acids which can be localized to pancreas and circulates in the blood at levels of the order of magnitude known for other hormones. These blood levels are increased by feeding. The peptide stimulates proventricular secretion and is glycogenolytic but not hyperglycemic in chickens. It is proposed to use immunoassay to study further the effect of feeding, crop distention, type of food etc. on plasma levels of the hormone in order to determine the specific factor or factors responsible for stimulation of secretion. Using C14 glucose and acetate the effect of the peptide on hepatic lipogenesis will be studied in chickens. Both types of studies will be performed in normal and partially pancreatectomized birds. An attempt will be made to isolate a pro- hormone.